自由场中正常青年人扩展低频听阈测试

为建立扩展低频测听的基准阈声压级，探讨影响结果的有关变量，在消声室中测试了３０名耳科正常青年人的纯音声场听阈和７名受试者振动阈值，频率包括４０Ｈｚ－４ｋＨｚ。结果（１）各受试者听阈沿其算术均数呈正态分布，扩展低频区阈值明显高于常规频区；（２）振动感仅出现于４０－５００Ｈｚ，各频率振动阈平均高于相应听阈３４ｄＢ以上。

Threshold of Hearing for Extended Low-Frequency Pure-tones under Free-field Listening Conditions

40 Hz to 4 kHz pure tone presented to 30 otologically normal young adults in ane-choic room,with special attention paid to the extended low-frequency region(below 125 Hz), vibrating thresholds were also evaluated in 7 subjects. It was found that the individual hearing thresholds were normal distributed around the arithmetic mean and decreased rapidly with the raised frequencies. Vibrotactile sensation could only be elicited in the higher sound pressure levels than that of hearing between 40 to 500 Hz. This indicated that normal human hearing was more sensitive in high frequencies than that in low,and vibrating feelings did not play a significant role in the evaluation of normal hearing in sound field. Ambient noise of the test room and signal characteristics of audiometric system seem to be the two main variables during the extended low-frequency hearing tests. The present data were compared with ISO 226-1987 and some other reports.